public int size()

in src/main/java/org/apache/commons/collections4/map/ConcurrentReferenceHashMap.java [1823:1866]
40 lines of code
12 McCabe index (conditional complexity)

    public int size() {
        final Segment<K, V>[] segments = this.segments;
        long sum = 0;
        long check = 0;
        final int[] mc = new int[segments.length];
        // Try a few times to get accurate count. On failure due to
        // continuous async changes in table, resort to locking.
        for (int k = 0; k < RETRIES_BEFORE_LOCK; ++k) {
            check = 0;
            sum = 0;
            int mcsum = 0;
            for (int i = 0; i < segments.length; ++i) {
                sum += segments[i].count;
                mcsum += mc[i] = segments[i].modCount;
            }
            if (mcsum != 0) {
                for (int i = 0; i < segments.length; ++i) {
                    check += segments[i].count;
                    if (mc[i] != segments[i].modCount) {
                        // force retry
                        check = -1;
                        break;
                    }
                }
            }
            if (check == sum) {
                break;
            }
        }
        if (check != sum) {
            // Resort to locking all segments
            sum = 0;
            for (final Segment<K, V> segment : segments) {
                segment.lock();
            }
            for (final Segment<K, V> segment : segments) {
                sum += segment.count;
            }
            for (final Segment<K, V> segment : segments) {
                segment.unlock();
            }
        }
        return sum > Integer.MAX_VALUE ? Integer.MAX_VALUE : (int) sum;
    }